The Declaration isn't some singularity that has no preceding context. The movement towards independence was already well underway, and that was inspired by the works of many writers, notably including Locke. Good grief, even the very authority YOU have cited -- James Otis -- acknowledges that. 
In the same sentence. Gee. I wonder what they had in common?
Of course only one of them used the word "Citizen."
In addition to the opening premise of your argument being faulty, you have the added problem of merely then assuming that "natural born citizen" as understood and used within the Convention had some Vattel-based meaning...
Demonstrated by the usage of the word "Citizen." Locke, and English common law both used the word "Subject."
even though 1) Jefferson was not in attendance,
Which has not a D@mn thing to do with anything.
2) in the period between the Declaration and the Convention many used "subject" and "citizen" in interchangeable fashion,
Better proof for my side than for yours. This was obviously a transition period where the word "Citizen" was slowly acclimating the populace to the change in their relationship to the government. The word "Subject" means "servant." The philosophical change is intended to demonstrates that each man is free and equal.
and 3) the "it comes from Vattel" argument so obviously is some Internet-blog driven piece of anachronistic projection based on a translation of Vattel...
The Declaration unquestionably is the result of Vattel's influence. Even your Fogbow kook friends have acknowledged that.
"Citizenship" comes from the Declaration of Independence.
Ergo, Citizenship is the product of a document and philosophy based on Vattel.
from 1796 first using the term "natural born citizen."
And that of course, is just they typical fogbow driven deception. Once again, the founders all read the book in French. The title of Chapter 19 is "Des citoyens et naturels". "Natural Citizens." The "born" part is an English leftover, but that is just an adjective for the word "Citizen" which is the noun.
John Jay grew up speaking French. Jefferson was fluent. It was considered a normal part of the education of a Gentleman at that time.
Are you going to make a valid point or something?
no support among credentialed historians or legal scholars.
I always find it funny when people trot out the old "Argumentum ad Verecundiam" in support of their losing effort to convince.
Maybe these authorities are just not diligent enough, or perhaps had some sort of Agenda?
In the same sentence. Gee. I wonder what they had in common? Hmmm, gosh, could it be that Locke and Vattel both wrote on natural law and the essential dignity of man, that both wrote about the right to revolt when natural rights were denied, that both were writers whom Jefferson drew upon when writing the Declaration?
These are all true. Which means they put the lie to your previous claims "John Locke does not declare a natural right to revolution and Independence" and "Indeed, the very ideas of "Revolution" and "Independence" comes from Vattel, and no one else." Your historical illiteracy was on full display there: Locke quite evidently wrote of the right of revolution, as James Otis (your source) notes.
And the Colonists were "subjects" reading Locke who wrote of the right of "subjects" to revolt. Somehow his relevance sails over your head. Was Jefferson's Declaration influenced by Locke? Indeed it was:
"Thomas Jefferson ranked Locke, along with Locke's compatriot Algernon Sidney, as the most important thinkers on liberty. Locke helped inspire Thomas Paine's radical ideas about revolution. Locke fired up George Mason. From Locke, James Madison drew his most fundamental principles of liberty and government. Locke's writings were part of Benjamin Franklin's self-education, and John Adams believed that both girls and boys should learn about Locke. The French philosopher Voltaire called Locke "the man of the greatest wisdom. What he has not seen clearly, I despair of ever seeing." . . . Locke's influence was most apparent in the Declaration of Independence, the constitutional separation of powers, and the Bill of Rights." Source
Here's from the folks at Monticello:
""I see my job as trying to bring together and harmonize a variety of different opinions," Jefferson wrote. "We are putting before all of mankind words that are both simple and firm, a justification for the stand that we're being forced to take."
Influences on Jefferson's Writing
Thomas Jefferson used no books or pamphlets to help him write the Declaration of Independence. But since his early days, he'd thought and read about government and the rights of mankind. He read British writer John Locke, who believed that people are born with natural rights. Governments should be for the benefit of everyone, not just the rulers. (These ideas were evident in Jefferson's ideas for Virginia's new state constitution.) Thomas Paine had also expressed a similar idea in Common Sense: "A government of our own is a natural right." Source
One more, just for fun and so I can laugh again when you purport to ignore it using your stupid evasion that Locke didn't use the term "citizen."
There has been considerable scholarly debate about how much Locke's political doctrines affected the American revolutionaries and the writing of the American declaration of independence. The original claim that Locke's thought had considerable influence on the colonists was challenged and has more recently been reaffirmed. Source
Speaking of "citizen," was that term so unique to Vattel insofar as writers influencing Jefferson that you establish your claim that "citizen" derives from Vattel? No, it wasn't.
Another strong influence on Jefferson was Jean Jacque Rousseau:
"If the American Revolution was due to the spirit of liberty inherent in the English people, the formulas in which the Declaration of Independence was couched were largely drawn from Rousseau. When its framers demanded "life, liberty, and the pursuit of happiness" for every citizen, they were speaking his language."Source
And Rousseau's "The Social Contract" is replete with discussions on that term "citoyen" that you think Jefferson could only have taken from Vattel.
You espouse a flawed theory based on selective sampling and tunnel vision by which you will only consider Vattel as the source.
Of course only one of them used the word "Citizen."
And when those Colonists reading Locke and Vattel were then subjects, why is that significant? Answer: it's not. It's just your self-serving dodge to try in vain to make Vattel some singular influence (a claim I've disproved above).
Demonstrated by the usage of the word "Citizen." Locke, and English common law both used the word "Subject."
And given many used "subject" and "citizen" interchangeably, so what? As far as the birthright issue goes, it is a distinction without a difference.
"Citizenship" comes from the Declaration of Independence.
That is the point of demarcation for viewing people as U.S. citizens. Though the concept of "citizenship" dates back to ancient Greece and Rome. Rousseau wrote on it, and Rousseau strongly influenced Jefferson and the Declaration. So while you can demonstrate the Declaration marks the start of U.S. citizenship, you fail to demonstrate the concept of "citizen" in the Declaration derives from Vattel.
Ergo, Citizenship is the product of a document and philosophy based on Vattel.
This is pure hand-waving fallacy on your part. You don't demonstrate this. You merely declare it because this has become your point of last refuge.
A reminder here on the course of this discussion is in order. You first started with me trying to argue that Wong Kim Ark had nothing to do with "natural born citizen." Then I disabused you of that ill-informed opinion, and you've abandoned it. Then you were all big on how Justice Gray misread the legislative history to the 14th Amendment. Then I disabused you of that ill-informed opinion, and you've since abandoned it. Then you fell back on the "it all started to go off-track with Rawle" argument. So I then showed how Story, Kent, Tucker, and Swift -- writing at the same time and even earlier than Rawle -- espoused the same jus soli principle, which puts the lie to your claim about Rawle. And along the way, I've been repeatedly hammering you on how the documented continued use of "natural born subject" and its interchangeable use with "NBC" in the post-Declaration period makes the ECL basis for "natural born citizen" in the Constitution self-evidenct (a fact reflected by the VAST majority of legal scholars and the courts since the Constitution was enacted).
Now, on this Constitutional issue, your main point has become the Declaration of Independence. And even here you can't prove your claim that "citizen" comes from Vattel, given that Jefferson acknowledges drawing upon multiple sources, and at least one highly influential source (Rousseau) also wrote of "citizens."
The title of Chapter 19 is "Des citoyens et naturels". "Natural Citizens." The "born" part is an English leftover,
And with that last remark you effectively concede the argument. Exactly!! Speaking of "natural born" citizens aligns the term with the common law. Had the Framers intended to match Vattel, it would have been a simple matter to write in Article II "born of citizen parents." (Vattel: "of parents who are citizens.") But they didn't. Instead, they framed this borrowing the nomenclature of English common law ("natural born" citizen).
The rest, as they say, is history. And your argument fails accordingly.
I always find it funny when people trot out the old "Argumentum ad Verecundiam" in support of their losing effort to convince.
Citing authorities who are recognized as being authoritative on the topic is both commonplace and proper. That's how "authorities" are recognized as such. They are influential and their works are cited. So we can observe Swift being cited. We observe Tucker, Kent, and Rawle being cited. We can observe Chancellor Sandford in Lynch v. Clarke being cited.
But Samuel Roberts? LOL. I've never seen him cited till Ray76 pulled him out of obscurity here. It was only with difficulty I found a bio on Roberts when I looked him up. Your fallacious appeal to "Argumentum ad Verecundiam" is just your lame attempt to dodge the fact the vast amount of authority on this topic is arrayed against you.